find intersection points and edge points

As you see in figure, I have a binary image which has been thinned. It contains English letters, some letters have intersection points (marked with red circles), and some don’t have those.

I want to extract intersection points for every litter and put it in a cell or whatever. I also want to extract the edge points (marked with blue circles) and put it in a cell or matrix to use it later.

In fact I have tried to write function but I could not execute it. So I hope that our teachers here help me.

Note: intersection points are pixels have more than two pixels in a neighborhood, while edge points have just one pixel.

Thank you

[Puja Das]

I want the code please send me [e-mail]

[Image Analyst]

Puja: Did you scroll down to here? Source code is there. Why email it to you when you can get it right there?

Answer 1

[Image Analyst]

This functionality is built into the bwmorph() function:

bpImage = bwmorph(binaryImage, 'Branchpoints');
epImage = bwmorph(binaryImage, 'Endpoints');
% Plot blue circles over branchpoints
[ybp, xbp] = find(bpImage);
hold on;
plot(xbp, ybp, 'bo', 'MarkerSize', 15);
% Plot red circles over endpoints.
[yep, xep] = find(epImage);
hold on;
plot(xbp, ybp, 'ro', 'MarkerSize', 15);

[majed majed]

Great thanks for your help

[swathi]

What modification should be brought in the given code, for image with white background & signature in black. Please help

[swathi]

I mean, to obtain the end points of the signature, where in, image has white background & signature in black. Kindly help.

Answer 2

[Robert]

Attached i send you a m.file. It finds the edge points right. For the intersection points, there is still some error, but the file can maybe help you as a draft.

Regards, Robert

[majed majed]

Thank you for your help